Hardie® Trim Boards

Critical Installation Rules

1. 1

   Trim is decorative and non-structural. Install it over wood or steel backing and never in contact with standing water

2. 2

   Face nail with 2 in. (50 mm) 16 ga finish nails into wood framing, or ET&F or equivalent fasteners into steel. Do not staple

3. 3

   Finish nails no closer than 13 mm (1/2 in.) to an edge, other fasteners 19 mm (3/4 in.), at least 25 mm (1 in.) from ends and a maximum 406 mm (16 in.) apart

4. 4

   Clearances: 203 mm (8 in.) to grade, 50 mm (2 in.) to decks, paths, steps, driveways and roofing, 6 mm (1/4 in.) above horizontal flashing (never caulked), 12 mm (1/2 in.) under cover

5. 5

   Flashing is required over every horizontal trim run, lapped under the water-resistive barrier

6. 6

   Windows: cap-over method, with a 3 mm (1/8 in.) caulked gap between siding and side trim and a 6 mm (1/4 in.) uncaulked gap between siding and head flashing

7. 7

   Splice long corners with weather cuts of at least 22.5° sloping down and away, and keep splices on adjacent corner boards 305 mm (12 in.) apart

8. 8

   Fascia: James Hardie's guide calls for a solid 2x subfascia (its instructions also allow rafter tails with 8d siding nails, never finish nails) and recommends the fascia be no more than 50 mm (2 in.) wider than the subfascia. Hang gutters through the roof sheathing into the rafter tails, not from the trim

9. 9

   Install frieze boards before lap or shingle siding, and caulk where the siding butts to them

10. 10

    Fasteners must be corrosion resistant. Hot-dipped galvanized is recommended, and stainless steel near the ocean, large bodies of water or in very humid conditions

11. 11

    Drive fasteners perpendicular and snug. Do not over drive, under drive or angle them, and do not use aluminum fasteners, staples to the wall, or clipped head nails

12. 12

    James Hardie's installation videos are filmed for the United States. Where a video and the Canadian HZ5® instructions differ, the Canadian instructions govern

Storage & Handling

• Store flat, dry and covered, in the original packaging on a pallet off the ground. Add a waterproof cover outdoors
• Carry pieces on edge and protect the edges and corners. Do not roll or dump the load off the truck
• Installing product that is wet or saturated can cause shrinkage at the joints. If it gets soaked, lay it flat and let it dry completely first
• Wipe construction dust off ColorPlus® product with a wet soft cloth or soft brush, then rinse with a garden hose
• Touch up nicks, scrapes and nail heads sparingly with the ColorPlus® touch-up applicator. Anything larger than a dime means replacing the piece
• Do not let ColorPlus® touch-up freeze, and apply it only when the air and the product are above 4°C (40°F)
• Problems caused by third-party touch-up paint are not covered by the ColorPlus® finish warranty, and James Hardie does not approve caulk or patching compound for touching up ColorPlus®
• Do not caulk nail heads on ColorPlus® product
• Terminate field cut edges into trim and caulk where possible. Seal every other cut edge with the ColorPlus® edge coater
• Remove the protective laminate sheet as soon as the piece is installed
• On ColorPlus® trim, nail through the laminate sheet, touch up the nail head through it, then remove the laminate
• Caulk, paint or prime every field cut edge
• Paint primed product within 180 days of installation. A 100% acrylic topcoat is recommended; back-roll if it is sprayed
• Do not use stain, oil or alkyd based paint, or powder coating. Do not paint product that is wet
• Sealant: elastomeric to ASTM C920 Grade NS Class 25 or higher, or latex to ASTM C834, per NBC 9.27.4
• Cut outdoors. The best method is a circular saw with a HardieBlade® and vacuum dust collection. Never power cut indoors, and never dry sweep the dust
• Fibre cement dust contains respirable crystalline silica. Use dust control and follow your provincial occupational health and safety rules